Corundum-mullite Honeycomb Ceramics
A brief introduction to corundum-mullite honeycomb ceramics.
Corundum-mullite Honeycomb Ceramics
Corundum-mullite honeycomb ceramic is a porous ceramic material with corundum (α-Al₂O₃) and mullite (3Al₂O₃•2SiO₂) as the main crystalline phases, manufactured using an extrusion molding process to form a honeycomb structure. This material combines the high-temperature strength of corundum with the thermal shock resistance of mullite, and is widely used in high-temperature heat storage, flue gas purification, and molten metal filtration in industries such as metallurgy, chemicals, and building materials.
Material Composition
Corundum phase: Provides high hardness, high wear resistance, and high-temperature strength.
Mulllite phase: Contributes to the material's low coefficient of thermal expansion and thermal shock resistance.
The two phases combine to form an interwoven structure, resulting in superior overall performance compared to single-phase materials. Depending on the application conditions, components such as zirconium corundum and chromium corundum can be added to improve slag resistance and corrosion resistance.
Preparation Process
Raw Material Mixing: Powders such as corundum, mullite, alumina, and clay are mixed with additives such as cellulose, glue, and water to form a plastic clay.
Extrusion Molding: After vacuum kneading, the clay is extruded into a honeycomb-shaped blank. The pore shape can be designed as square, hexagonal, or circular.
Drying and Sintering: After drying, the blank is sintered at a high temperature of 1400-1650℃ to form a stable crystalline structure.
Main Performance
Performance Dimensions | Indicator Characteristics |
Operating Temperature | Long-term 1450℃, short-term up to 1650℃ |
Coefficient of Thermal Expansion | ≤6×10⁻⁶/℃ at 200-800℃, good thermal shock resistance |
Compressive Strength | Axial >32MPa, Radial >21MPa |
Temperature Conductivity | 1.5-2.5 W/m•K, beneficial for heat storage and exchange |
Structural Characteristics | Aperture ratio 50%-67%, specific surface area 280-1065 m²/m³, low pressure drop |
Typical Applications
Heat-Regenerative Combustion Systems (HTAC)
As a heat regenerator in industrial furnaces such as regenerative heating furnaces, heat treatment furnaces, and forging furnaces, it utilizes parallel, straight-through channels to achieve low-resistance, high-efficiency heat exchange, recovering waste heat from flue gas to preheat combustion air, resulting in energy savings of 30%-50% and reduced NOx emissions.
Industrial Flue Gas Purification
Used in denitrification (SCR) systems in thermal power plants, waste incineration plants, and chemical plants as a catalyst carrier or filter medium to treat NOx and other harmful gases in flue gas.
Melted Metal Filtration
Used as filter elements in aluminum and copper alloy casting to remove inclusions from the melt and improve casting quality. The hexagonal shape facilitates assembly and coverage of large-size runners.
Chemical Catalyst Carrier
Used as a catalyst support or tower packing in fixed-bed reactors for processes such as contact combustion and pyrolysis.
Common Specifications
Dimensions: 100×100×100mm, 100×100×150mm, 150×150×150mm, 150×150×300mm, etc.
Shapes: Square, cylindrical, hexagonal
Hole Types: Square, hexagonal, circular, rectangular
Hole Density: Various specifications from 10×6 holes to 42×28 holes
Wall Thickness: 0.55-4.0mm, adjustable according to hole diameter and strength requirements
Selection Considerations
Operating Temperature: Standard type is suitable for long-term use below 1450℃; for higher temperatures, modified components such as zirconium corundum need to be added.
Flue Gas Characteristics: When containing dust, tar, or corrosive components, choose improved materials with strong slag resistance.
Pressure Drop Requirements: For systems sensitive to pressure drop, select products with high porosity and regular pore structure.
Mechanical Strength: For applications subjected to airflow impact and self-weight pressure, compressive strength indicators need to be checked.
Size Matching: Select square (assembly) or cylindrical (direct installation) shapes based on the internal cavity shape of the equipment.
Summary
Corundum-mullite honeycomb ceramics achieve a balance between high-temperature strength and thermal shock resistance through multiphase design. Its regular pore structure gives it significant advantages in industrial applications such as heat storage, filtration, and catalysis. With increasing industrial energy conservation and environmental protection requirements, the application of this material in high-temperature flue gas treatment and waste heat recovery will continue to expand. Selection should comprehensively consider factors such as temperature, medium, pressure drop, and strength based on specific operating conditions. We are a Chinese industrial ceramics manufacturer. For more information, please contact us via email at annayu@169chem.net or WhatsApp +8618909016373.